social environment factors. if mom is unskilled worker and unemployed that rate jumps to 15%. race also plays a factor. in this calculator tailor into the u.s. market. if mom and dad are sort of a little bit overweight, mom gained 25% extra weight when pre of the baby is asian, 7% chance that baby will become obese. if the baby is black that jumps to 30%. they looked at 4,000 people in finland over 25 years to come up with a basic calculator and worked with harvard to come out that with that u.s. >> shepard: it also works to exercise and eat right. >> difficult to exercise and eat right when you are six weeks old, shep. what this tells us is that the very earliest stages of life which children are at risk becoming obese. typically you don't find out 3 or 4. many children it's too late to go back. have you got to get them at the earliest ages of life says the professor who led this study. >> we don't have the magic box for presenting a ability. we only say it's very easy to detect that people have choice. now it's time to try to do something to prevent obesity in this part of t